Evacuated vessel and method of manufacturing the same



Dec. 15, 1931.

c. D. HAIGIS EVACUATED'VESSEL AND METHOD OF MANUFACTURING THE SAME Filed Dec. 31 2 2 Sheets-Sheet Dec. 15, 1931. c HAIGIS 1,836,5 90

EVACUATED VESSEL AND METHOD OF MANUFACTURING THE SAME Filed Dec. 3l 192 2 Sheets-Sheet 2 Patented Dec. 15, 1931 UNITED STATES PATENT OFFICE CABLETQN D. EAIGIS, O1 EADDONFIELJD, NEW JERSEY, ASSIGNOR, BY MJBSNE ASSIGN- MENTS, TO RADIO CORPORATION OF AMERICA, 01 NEW YORK, N. Y., A. CORPORA- TION OF DELAWARE EVACUAT'ED VESSEL AND METHOD OF MANUFACTURING TEE SAME Application filed December 81, 1924. Serial No. 759,115.

vide an incandescent lamp by extending the conductors or lead-in wires for the lamp filament directly through apertures in the bottom of a surrounding glass bulb, but lamps of this type have been defective for reasons well known in the art. Accordingly it is now the usual commercial practice to seal the lead-in wires for the filaments of incandescent lamps, or for the various inner elements of thermionic valves, in the upper end of a hollow, glass supporting member, or press, to seal the base of this press in the lower open end of the surrounding glass bulb, and to anchor the outer ends of said lead-in wires, by the use of solder, in a base which is secured to the glass bulb by means of suitable cement and a metallic base cap. In order that the lamp or valve may be securely held by a socket, a radially promoting metal pin is secured to the outer surface of the metallic base cap, or the latter is threaded. Lamps and thermionic valves of this ty e are not only expensive to manufacture, ue to the large number of elements and different substances employed, but also this method of manufacture causes more or less trouble because of loose and defective contacts resulting from the use of solder, and the difiiculty of rigidly securing the metallic base cap or sleeve to the glass bulb. These defects and difficulties are of particular importance where the lead-in wires increase in number.

Vacuumtubes of the above type, moreover, which employ a press for the lead-in wires, may have their action entirely destroyed or seriously interfered with by the potential difference between said lead in wires, and this is particularly true when the volta e applied between the electrodes is large. parking may result between the lead-in wires, or the press may become so highly heated, due to dielectric hysteresis, as to raise the temperature of the glass to a point where elecv trolysis sets in, thereby destro ing the airtight seal around the lead-in wires. Various expedients have heretofore been proposed to remed the above defects. For example, a metalhc band has been positioned over the upper end of the glass press and one of the cathode lead-in wires has been connected to this band. A second metallic band sur rounding the lead-in wires has also been provided around the inner surface of the press to prevent the above mentioned spark ing. It has further been proposed to seal the anode lead-in wire directly in the base of the tube while the cathode and grid leadin wires are sealed in the press in the usual manner. Such expedients, however, are doubl expensive since they still require the use 0 the usual porcelain plug, solder, metallic base ring, and cement.

The use of a press always requires the use of a base plug in order that the lead-in wires may be properly spaced apart and anchored in contact-making position relative to the socket leads. Moreover, even if the voltages applied to the valve are not unusually large, the close spacing of the lead-in wires necessitated by the use of the press, results in a large capacity loss.

An object of the present invention is to overcome the above defects by providing a novel vacuum tube or thermionic valve having an outer envelope formed entirely of glass or other suitable dielectric, the device being so constructed that the necessity for the usual press, porcelain plug, solder, cement, and metallic base ring is eliminated.

Another object of the invention .is to provide novel means for mounting the inner elements, such as a filament. grid and plate, within the glass envelope.-

A further object is to provide novel means for positioning and locking the valve or tube in a socket.

Another object of the invention is to provide new and improved means whereby capacity losses are greatly reduced or practivacuum tube or thermionic valve having an Another object of the invention is to provide a method of manufacturing a device of the type characterized so that the same may comprise an integral disk-like base which will rigidly maintain the conductors in wide ly spaced relation and in contact-making position. Other objects will appear as the description of the invention proceeds.

The invention is capable of receiving a variety of mechanical expressions, and of being carried out in a variety of ways, some of which are shown on the accompanying drawings, but it is to beiexpressly understood that the drawings are for purposes of illustration only and are not to be construed as a definition of the limits of the invention, reference being had for that purpose to the appended claims.

In the drawings,

Fig. 1 is a side elevation partly in section illustrating one embodiment of the present 7 invention;

Hi2 is a view similar to Fig. 1, the devicein which the socket retainlng means may be formed; 1

Figs. 8 and 9 are diagrammatic side ele; vations illustrating two ways in which the method of manufacturing the improved device may be carried out;

Fig. 10 is a bottom plan view illustrating one manner in which the lead-in wires may be sealed in the bottom of the glass envelope; and

Fig. 11 is a detail perspective view illustrating one form of locating boss that may be provided for the device.

Referring to the drawings wherein likereference numerals refer to like parts throughout the several views, 12 is a glass envelope that is provided on its disk-like base 13 with a plurality of hollow projections or bosses 14 which are preferably widely spaced and positioned adjacent the periphery of the base. While the envelope 12 may be formedof glass such as is ordinarily used in the manufacture of devices of this character, said envelope is preferably molded. from quartz, pyrex, or any suitable boro-silicate having low dielectric losses.

Mounted in any suitable way within the envelope 12, are the usual electrode elements.

The particular characteristics of these elements, and the number employed, form nopart of the present-invention. In the form shown, the mounting comprises a centrally disposedcolumn 15 that is preferably formed of glass and is rigidly secured in any desired manner to the inner surface of the disk-like base '13, as by sealing or fusing the same to the base.

Formed integrally with colunm 15 and extending upwardly within the envelope 12, from adjacent the upper end of said column,

is a substantially rectangular frame member 16 which is also preferably formed of glass. The upper end of column 15 terminates at a point a short distance above the lower side "*qf frame '16 ina plurality of radially ex-- tending arms. As shown, these arms comprise a horizontal portion 17 a which terminates in an integrally formed vertical portion 176, the latter preferably being in alignment with the hollow bosses 14. The arms 17 Y may be so arranged relative to the rectangular frame 16 that each forms an angle of substantially 45 with the vertical plane passing through said frame'.

Extending through the center of the vertical' portions 176 of arms 17, and rigidly sealed therein, are the lead-in wires 18 for the electrode elements, which extend downwardly through the hollow bosses 14 in the disk-like base of thetube, to points slightly below the lower ends of said bosses, as indicated at 1842. It will be understood that the lead-in wires 18 may be provided with a suitable coating where they pass through the bosses 14 and portions 176 in order that said wires may have a co-efiicient of expansion equal to that of the glass envelope, thereby insuring that the vacuum in the tube will not be destroyed. The projecting portions 18a of the lead-in wires 18 are adapted to engage the necessary elements in the socket to complete the various circuits. The arrangement of lead-in wires as shown greatly strengthens'thef mounting of the electrode elements and rigidly braces the supporting column 15.

The device of the present invention does not include the usual porcelain base plug, or metallic base ring for securing the plug to the glass envelope, and novel means are provided for looking or positioning the device in the usual socket. The almost universal practice at present is to employ a bayonet joint connection between the vacuum tube and the socket, the tube being provided with a radially projecting metallic pin carried by the metallic base ring. In the present invention a projecting pin 19 of glass which is integrally formed with the envelope 12 may be'provided in place of the usual metallower portion of the tube or valve may be provided with an annular recess or, preferably, an arcuate recess 21, or less than a complete annulus, to receive a metallic ring or' segment 22 provided with a radially extending pin 23. Preferably, the member 22 does not constitute a com lete metallic circuit around the tube, and if a. complete ring is used it is provided with aninsulating section in order to prevent spurious induced currents from flowing in it during the use of the tube. In the preferred form of the invention, however, the envelope 12 has molded therein a vertically extending slot 24 formed partly in the base portion 13 and partly in the vertical side wall of the envelope. Into the slot 24 is cemented or forced a piece of metal or of insulating material 25, provided with a pin 26 for engagement with the bayonet joint of the socket. If it is desired to employ the tube in a socket which does not require the use of a bayonet joint connection, a dummy boss or pin 27 may be formed similarly to the hollow bosses 14 on the disk-like base. This dummy boss will insure the tube being positioned in the socket in such a manner that the electrodes will be placed in electrical communication with the desired outer circuits. If desired, one of the hollow bosses 14 may be given a unnusual shape or size in order that it may perform the functions of the boss 27, thereby rendering the latter unnecessary.

Any suitable method may be employed for manufacturing my improved thermionic valve but preferably this method consists in molding the base of the tube integral with the bulb by any of the methods familiar to those skilled in the art. The mold is so formed that the disk-like base of the envelope is provided with a suitable number of integral hollow bosses or extensions 14, depending on the number of lead-in wires employed in the particular form of tube being manufactured, this being three or more in the case of thermionic valves. The envelope is also.

provided with one of the above described means for locating and retaining the completed tube in the socket.

In the method of procedure diagrammatically illustrated by Figs. 9 and 10, the upper portion of the envelope is open, and the supporting glass frame 16 with its elements complete, together with the lead-in wires 18, are inserted in the envelope through the upper open end, the lead-in wires being passed through the hollow glass extensions 14 in the disk-like'base, by means of a suit able machine well known to those skilled in the art. Flames 28 are then caused to play on each of the hollow bosses 14, thus fusing or sealing the leadin wires in vacuum tight joints. Means may be provided on the sealing machine for pressing the glass firmly around each wire by 'means of metal fingers 29 which and bulb may be separately molded, and if this method is pursued, the glass frame 16, its supporting rod 15, and the elements carried thereby are properly positioned and fused into the base in the manner heretofore described. The final operation consists of fusing the bulb already fashioned onto the base on which are previously mounted the inner elements. A

If desired, the lead-in Wires 18 may be surrounded by glass tubes 30, preferably of glass having a low dielectric loss, ktending for a greater or less extent from the lower end of the vertical arm portions 17?) to the inner surface of the disk-like base 13. These tubes may be formed integral with the arm portions 17b and may be fused to said base at the same time that the wires 18 are sealed in the hollow bosses 14 or they may be glass tubes merely slipped over the lead-in wires during the assembly of the parts.

It will, therefore, be observed that the expense and assembling cost of the porcelain plug, brass cap or base member, and the cement for securing the same to the bulb, are eliminated, while the frame 16 and supporting column 15, together with the disk-like base 13 and bosses 14, eliminate the necessity for the usual press now employed. The wide spacing of the lead-in wires eliminates the objectionable capacity losses and insures that the action of the tube will not be destroyed by sparking. The mounting for the electrode elements is particularly rigid due to the strenghthening and bracing effects of the lead-in wires. The means provided for locating and retaining the tube in a socket are efficient and inexpensive and avoid the effects produced by spurious currents induced in the metallic base ring now employed. The tube is simple and rugged in construction and may handled with the same facility as the vacuum tubes now in use.

Vhile the embodiments of the invention illustrated on the drawings have been dein details of construction, arrangement, and- 5 stantially fiat or slightly curved base, whether concave or convex, but excludes a base formed of the usual type of press. It is apparent that the invention is applicable to vacuum tubes of the two electrode type as well as to those employing three or more electrodes, and the invention is also applicable to evac-' uated vessels containing electrical conductors other than vacuum tubes. Reference is therefore to be had to the claims hereto appended for a definition of the limits of the invention.

What is claimed is 1. Adevice of the class described comprising an evacuated envelope formed entirely of glass and having an integral supporting base, a glass column secured to the base of said envelope having a plurality of radial arms, electrodes supported by the column,

' and lead-in wires connected to the electrodes and-sealed in said base and arms, whereby the necessity for a metal ,base is eliminated.

2. A device of the class described comprising an eva uated envelope having an integral disk-like siipporting base, a plurality of electrodes in said envelope, lead Wires for said electrodes, means for supporting said electrodes,"and means surrounding each of said lead wires and sealed in said base for bracing said supporting means. 5

3. A device of the class described comprising an envelope having an integral disk-like base provided with-la plurality of bosses, a supporting member including a plurality of radially supported arms in alignment with said bosses, electrodes located in said envelope, and lead-1n wires connected with said electrodes and sealed'in said bosses and arms,

whereby said electrodes are rigidly supported.

4. A device of the class described comprising an evacuated envelope having an integral disk-like supporting base provided with a plurality of integral depending bosses, said envelope and base being adapted for use with outa metal base, supporting means mounted in said envelope, electrodes carried by said supporting means and lead-in wires connected to said electrodes and sealed in said bosses, the outer ends of said lead-in wires being extended beyond the ends of said bosses to form contact members adapted to directly engage the contacts of a socket.

5. A device of the class described comprising an evacuated vessel having a disk-like base, a column mounted on the inner surface of said base, a frame carried by said column, a plurality of arms carried by said column and spaced apart at equal intervals, electrodes locatedin said vessel, and lead-in wires connected with said electrodes and sealed in said base and said arms, whereby said electrodes are rigidly supported.

6. A device of the class described comprising an evacuated vessel having an integral disk-like base provided with a pluralit of bosses formed adjacentthe periphery of the base, a supporting column mounted on the base, a frame secured to said column, electrodes carried by the frame, a plurality of radial arms carried by said column, each of said arms having a horizontal portion, and a vertical portion in alignment with said bosses, lead-in wires for the electrodes sealed in said arms and in said bosses, and insulating means surrounding each of said Wires.

7. A device of the class described comprising an evacuated envelope having an integrally formed disk-like base, means forming a groove in said envelope, a supporting member secured to said base, electrodes carried by said supporting member, lead-in wires for the electrodes sealed in said base, and socket formed in said envelope.

8. A device of the class described comprising an evacuated envelope having an integral disk-like base, a frame engaging said base, a plurality of electrodes carried by said frame, lead-in wires for the electrodes sealed in said base, a member received-in said envelope, and socket engaging means carried by said member.

9. A device of the class described compris-- ing an evacuated envelope having an integral base, a frame including a plurality of radial arms having engagement with said base, electrodes carried by said frame, lead-in wires for the electrodes sealed in said arms and base, a member secured to the envelope, and a radially projecting pin secured to said member.

10. A device of the class described comprising an envelope having a disk-like base adapted for "use without the usual metal supporting member, supporting means including a plurality of arms in said envelope, electrodes carried by the supporting means, lead-in wires for the electrodes sealed in said base and said conductors sealed in said arms and bosses.

12-. A device of the class described including a dielectric envelope having a disk-like base and a recess formed in the side wall thereof, a plurality of bosses formedintegrally with said base, a plurality of electrodes in said envelope, lead-in wires for said electrodes sealed in said bosses, and socket engaging means extendingfrom said recess, whereby the necessity for the usual metal base is eliminated.

13. A method of manufacturing vacuum tubes which consists in molding the base of the tube integral with the bulb portion, sealing the support for the electrodes of the tube to said base, sealing the lead-in wires for the electrodes directly in the base, exhausting the bulb and sealing the same.

14. A method of manufacturing an allglass vacuum tube which consists in forming an open ended envelope by molding the base of the envelope integral with'the bulb portion, forming a plurality of hollow bosses on said base, introducing an electrode assembly in the envelope, sealing the lead-in wires of the assembly in said bosses, drawing down the upper part of the envelope and exhausting the same.

15. A method of manufacturing a vacuum tube which consists in molding an envelope open at one end, assembling electrode elements and lead-in wires on supporting means, introducing the assembly into the envelope, passing the lead-in wires through openings'in the base of the envelope, sealing the lead-in wires in the base, sealing the supporting means to the base, drawing down the upper. part of the bulb and exhausting the same. l

16. A method of manufacture whichconsists in molding a disk-like base integral with a dielectric envelope, assembling an electrical conductor on a frame, inserting theassembly in the envelope, passing theterminal portions of the conductor through openings in said base, sealing the terminal portions directly in the base, exhausting the envelope, and sealing the same.

17. A- method of manufacture which consists in molding a dielectric envelope, assemcludes molding a dielectric envelope, forming openings in the base of the envelope, assembling electrodes on a frame, sealing lead-in wires for the electrodes in said frame, inserting the assembly in the envelope, and sealing the lead-in wires in the base of the envelope.

19. A method of manufacture which includes molding a dielectric envelope, forming openings in the base of the envelope, forming a recess in the envelope, assembling electrodes on a frame, sealing lead-in wires for the electrodes in said frame, insertin the assembly in the envelope, sealin the flame to the envelope, sealing the lead-1n wires in the base of the envelope, and securing socket positioning means in said recess.

20. A method of manufacturewhich consists in molding a dielectric envelope, forming'openingsin the base of said envelo e, assemblingone or more electrodes on a rame, sealing lead-in wires for said: electrode or electrodes in said frame, connecting the electrodes and lead-in wires, positioning insulating means around said lead-in wires, inserting the assembly in said envelope, passing said lead-in wires through said openings,

sealing said wires in said base, and completmionic valves which includes molding the di electric envelope, forming openings in the base of the envelope, assembling electrode elements with lead-in wires connected thereto, inserting the electrode elements in said envelope with said lead-in wires passing through said openings, sealings the lead-in wires in said base, and exhausting and co1 npleting said envelope.

In testimony whereof I have signed this specification.

QARLETON D. HAIGIS. 

